Callio Therapeutics is a biotechnology company developing multi-payload antibody-drug conjugates (ADCs) to enhance cancer treatment. Headquartered in Seattle and Singapore, Callio is developing next-generation ADCs with differentiated payload and linker technologies that enable the targeted delivery of multiple therapeutic agents to tumor cells. This approach aims to overcome the limitations of conventional single-payload ADCs, potentially improving efficacy and patient outcomes.

The company’s lead program is a HER2-targeted dual-payload ADC, with a second undisclosed ADC program in development. Callio was founded by Frazier Life Sciences and launched with a $187 million Series A financing round, supported by leading life sciences investors, including Jeito Capital, Novo Holdings A/S, Omega Funds, and others.

Callio Therapeutics was established through an exclusive worldwide license agreement with Hummingbird Bioscience, securing its ADC platform, intellectual property, and pipeline assets. The company's leadership team brings extensive expertise from ProfoundBio, Silverback Therapeutics, SeaGen, Medarex, Genentech, and Hummingbird Bioscience.

With its novel ADC technology and strong investor backing, Callio Therapeutics is positioned to advance multi-payload ADCs as a transformative approach to cancer therapy.